|
|
|
|
|
Mesodma Mesodma is a genus of extinct mammal that lived during the upper Cretaceous and the Paleocene periods in North America. It was a member of the extinct order of Multituberculata and within the suborder of Cimolodonta, family Neoplagiaulacidae. This genus has been the subject of much revision. Also known as Cimexomys (partly); Cimolomys (partly); Halodon; Parectypodus (partly); Ptilodon (partly). The species Mesodma hensleighi is found in the Hell Creek Formation in the US and in Saskatchewan, Canada. They lived during the Campanian and upper Cretaceous. The holotypes for this species are in the collection of the University of Alberta. Individual members of this species weighed around 15 g. Species: Mesodma ambigua Place: Mantua Lentil, Wyoming Country: USA Age: Maastrichtian-Puercan, upper Cretaceous - Paleocene This has been cited as a possible descendant of M. thompsoni. It weighed about as much as a couple of well-fed mice (about 55g). Species: Mesodma formosa is also known as Cimolomys formosus; Cimolomys gracilis; Halodon formosus; M. formosus; and Ptilodon formosus Place: Hell Creek and Frenchman Formation Country: USA & Canada Age: Maastrichtian-Puercan, from the upper Cretaceous to the Paleocene. This species is possibly also known from Utah. Individuals weighed about 30g. Species: Mesodma garfieldensis Place: Hells Hollow, Montana Age: Puercan, lower Paleocene Individuals of this species probably weighed around 40g. Species: Mesodma primaeva Aka: Cimolomys primaevus; Parectypodus primaeva; Ptilodus primaevus Place: Montana and Wyoming, US Age: Campanian, upper Cretaceous lower Paleocene Species: Mesodma pygmaea Place: Gidley Quarry, Montana, as well as Wyoming and Alberta, Canada Country: USA & Canada Age: Torrejonian-Tiffanian, middle Paleocene This species was very pygmaea indeed. Individuals of this species weighed about 8g. Species: Mesodma senecta Age: Campanian, upper Cretaceous This species is in a further Alberta University holotype. Individuals of this species weighed about 50g. Species: Mesodma thompsoni Aka: Cimolodon nitidus; Cimolomys gracilis; Cimolomys nitidus Place: St Mary River Formation & Montana and Wyoming Country: Canada and USA Age: Maastrichtian-Puercan, upper Cretaceous - Paleocene Individual members of this species weighed about 55g. References - Osborn (1891); A review of the Cretaceous Mammalia. Proc. Acad. Nat. Sci., Phila.: 124 - 135.
- Simpson (1929), American Mesozoic Mammalia. Mem. Peabody Mus. Nat. Hist. iii (i): p.1-235.
- Clemens (1963), Fossil mammals of the type Lance formation Wyoming. Part I. Introduction and Multituberculata. Univ. Calif. Pub;. Geol. Sci. 48, p.1-105. (According to Peabody Museum database.)
- Marsh (1889), Discovery of Cretaceous Mammalia. Am. J. Sci. (3) xxxviii, p.177-180.
- Archibald (1982), A study of Mammalia and geology across the Cretaceous-Tertiary boundary in Garfield County, Montana. Univ. of Calif. Publ. Geol. Sci. 122xvi+, 286pp.
- Jepsen (1940), Paleocene faunas of the Polecat Bench formation, Park County, Wyoming. Pro. Amer. Philos. Soc, 83, p.217-341, 21 figs., 5pls.
- Kielan-Jaworowska Z & Hurum JH (2001), Phylogeny and Systematics of multituberculate mammals. Paleontology 44, p.389-429.
- http://home.arcor.de/ktdykes/ptilodon.htm Mesozoic Mammals; Ptilodontoidea, an Internet directory.
|
 |
|
| Copyright 2005-2009 OnPedia.com. All Rights Reserved |
|
|